Description: Adopt high quality carbide material, good flexibility and wear resistance. High precision, tight and stable clamping. Made of carbide, processing by heat treatment and precise grinding. Suitable for engraving machine, applicable to different specifications of the bit tool and chuck Good elasticity and abrasion resistance. High precise clamping force, good grip stability. Specification: Material: Carbide Color: As the Picture Shows Size: Approx. 6.35mm to 12.7mm: Inner diameter: 6.35mm/ 1/4 inch outside diameter:12.7mm/ 1/2 inch 6mm to 12.7mm: Inner diameter: 6mm/ 0.23inch outside diameter:12.7mm/ 1/2 inch 8mm to 12.7mm: Inner diameter: 8mm/ 0.31inch outside diameter:12.7mm/ 1/2 inch 10mmto 12.7mm: Inner diameter: 10mm/ 0.39inch outside diameter:12.7mm/ 1/2 inch Package Includes: 1 Piece Route Bit Chuck Adaptor 6.35-12.7mm 1 Piece Route Bit Chuck Adaptor 6-12.7m 1 Piece Route Bit Chuck Adaptor 8-12.7mm 1 Piece Route Bit Chuck Adaptor 10-12.7mm Note: Please allow 1-3mm error due to manual measurement, pls make sure you do not mind before you bid Due to the difference between different monitors, the picture may not reflect the actual color of the item, pls understand, thank you.